Decontamination methods are used in a broad range of applications, and have used an equally broad range of decontaminating agents. As used herein the term “decontamination” refers to the inactivation of bio-contamination, and includes, but is not limited to, sterilization and disinfection.
One common method for decontaminating an enclosure (e.g., a room) is to blow air through the enclosure in a continuous loop, i.e., from the enclosure, through a vaporized hydrogen peroxide (VHP) unit, and back into the enclosure. A typical VHP unit includes a blower, a catalytic destroyer, a dryer, a vaporizer, a preheater and an injection pump. The blower circulates the air through the continuous loop at a regulated flow rate. The catalytic destroyer breaks down vaporized hydrogen peroxide withdrawn from the enclosure into water and oxygen. The dryer removes water vapor from the air circulating therethrough. The pre-heater heats the air to facilitate the vaporization process. The vaporizer includes a heated surface to vaporize liquid decontaminant that is injected into the vaporizer by the injection pump. The injection pump controls the amount of decontaminant that is vaporized per unit time.
A VHP decontamination cycle is commonly divided into (4) four phases, namely, a dehumidification phase, a conditioning phase, a decontamination phase and an aeration phase. In the dehumidification phase, the relative humidity within the enclosure is reduced by using the dryer. After the dehumidification phase is complete, the conditioning phase commences, wherein vaporized hydrogen peroxide is injected into the enclosure at a relatively high rate to bring the vaporized hydrogen peroxide concentration up to a desired level in a short period of time. After the conditioning phase, the decontamination phase is run where the injection rate may be modified to maintain the hydrogen peroxide vapor in the enclosure at a constant concentration level. In the aeration phase that follows the decontamination phase, the enclosure is aerated by ending injection of the hydrogen peroxide vapor, and removing hydrogen peroxide vapor from the enclosure. The destroyer is used to break down the hydrogen peroxide vapor into water and oxygen. Aeration continues until the concentration of vaporized hydrogen peroxide in the enclosure is below a threshold concentration level (e.g., 1 ppm).
Existing VHP decontamination systems have several drawbacks. In this regard, the components of existing VHP decontamination systems can be heavy, thus making the components difficult to transport to a desired location. Components of existing VHP decontamination systems also may not have adequate capacity or features to properly decontaminate enclosures of various dimensions (e.g., large rooms or emergency vehicle enclosures).
The present invention provides a modular decontamination system that addresses these and other drawbacks of existing decontamination systems.